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United States Patent |
5,015,997
|
Strubbe
|
May 14, 1991
|
Method and apparatus for measuring combine grain loss
Abstract
An apparatus is provided for measuring grain loss in a harvesting machine
in substantially absolute terms. This apparatus comprises one or more
first detectors operable to detect one or more operating condition
parameters and to produce a first electrical output signal representative
thereof, a plurality of second detectors operable to detect grain
separation at a plurality of locations within the machine and to produce
second electrical output signals representative thereof, processor means
to which the first and second output signals are applied and operable to
derive therefrom a substantially absolute indication of grain loss at a
given instant, and display means for displaying the grain loss indication.
Inventors:
|
Strubbe; Gilbert J. I. (Zedelgem, BE)
|
Assignee:
|
Ford New Holland, Inc. (New Holland, PA)
|
Appl. No.:
|
524104 |
Filed:
|
May 16, 1990 |
Foreign Application Priority Data
| Apr 26, 1988[EP] | 882008022 |
Current U.S. Class: |
340/684; 56/10.2C; 56/DIG.15; 450/4; 450/5 |
Intern'l Class: |
G08B 021/00 |
Field of Search: |
460/4,5
56/10.2,DIG. 15
340/684
|
References Cited
U.S. Patent Documents
4036067 | Jul., 1977 | Strelioff et al. | 460/5.
|
4230130 | Oct., 1980 | Staiert | 460/5.
|
4296409 | Oct., 1981 | Whitaker et al. | 340/684.
|
4360998 | Nov., 1982 | Somes | 460/5.
|
4376298 | Mar., 1983 | Sokol et al. | 56/10.
|
4513562 | Apr., 1985 | Strubbe | 56/10.
|
Foreign Patent Documents |
0122343 | Oct., 1984 | EP.
| |
2044266 | Mar., 1971 | DE.
| |
2207563 | Aug., 1973 | DE.
| |
2430283 | Jan., 1976 | DE.
| |
2527090 | Jan., 1976 | DE.
| |
2126702 | Oct., 1972 | FR.
| |
2203582 | May., 1974 | FR.
| |
2143714 | Feb., 1985 | GB.
| |
Primary Examiner: Orsino; Joseph A.
Assistant Examiner: Jackson; Jill
Attorney, Agent or Firm: Miller; Larry W., Seemar; Frank A., Marquette; Darrell F.
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. Pat. Application Ser. No. 335,658,
filed April 10, 1990 now U.S. Pat. No. 4,951,031.
Claims
What is claimed is: PG,24
1. In an apparatus including detector means associated with a grain
handling mechanism in a crop harvesting machine for measuring grain loss
from said machine, said grain handling mechanism including threshing means
for threshing grain from crop material, separating means for removing
threshed graim from said crop material, and cleaning means in flow
communication with said separating means to receive separated grain
therefrom and clean trash material from said separated grain therefrom and
clean trash material from said separated grain to create cleaned grain,
said grain moving through said grain handling mechanism along a crop flow
path terminating at the discharge of said grain from said grain handling
mechanism, said crop material defining operating condition parameters
affecting the efficiency of said grain handling mechanism to harvest said
crop material, the improvement comprising:
at least two detector means associated with said grain handling mechanism,
each of said detector means being provided at spaced apart locations along
the length of the flow path of the crop material through said grain
handling mechanism and being operable to measure grain separation in said
grain handling mechanism at each said location within the machine and to
produce electrical output signals representative thereof; and
processor means programmed with a plurality of grain loss algorithms
against which the output signals are applied to derive therefrom a
substantially absolute indication of grain loss at a given instant, said
processor means being operable to select one of said algorithms for
utilization in response to said operating condition parameters, each said
algorithm calculating the absolute indication of grain loss using a ratio
of selected said output signals.
2. The apparatus of claim 1 wherein a first grain separation detector means
is associated with a portion of said grain handling mechanism at a
substantial distance forwardly of a discharge end thereof,
a second grain separation detector means being provided generally at said
discharge end of said grain handling mechanism.
3. The apparatus of claim 2 wherein a third grain separation detector means
is associated with said grain handling mechanism generally midway between
said first and second detector means.
4. The apparatus of claim 3 wherein each of the detector means is of the
impact type.
5. The apparatus of claim 3 wherein the processor means has stored therein
predetermined data in the form of look-up tables and is operable to
process the output signals of said grain separation detector means to
derive processed data indicative of grain loss, said processor means being
further operable to compare said output signals and said operating
condition parameters with said predetermined data to determine correction
factors for application against said algorithms to derive an absolute
indication of the grain loss from the grain handling mechanism.
6. The apparatus of claim 5 wherein the processor means is programmed to
multiply said correction factors times the algorithm to derive said
substantially absolute grain loss indication therefrom.
7. The apparatus of claim 5 wherein input means is provided for manually
inputting said operating condition parameters to the processor means, the
processor means being programmed to accept the manual input of said
operating condition parameters and being operable to compare said inputted
operating condition parameters with said predetermined data stored in the
processor means to derive therefrom said substantially absolute indication
of grain loss.
8. The apparatus of claim 7 further comprising further detector means
coupled to the processor means and operable:
to detect actual crop parameters corresponding to said operating condition
parameters;
to produce a further signal representative of said actual crop parameters;
and
to apply said further signal to the processor means, said processor means
being programmed to apply said further signal against the predetermined
data stored within the processor means and the data derived from the
output signals of the grain separation detector means to derive therefrom
said substantially absolute indication of grain loss.
9. The apparatus of claim 8 further including a harvesting speed detector
operable to produce signals indicative of the surface area being harvested
by said machine, said processor means being programmed to divide the
signals derived from the selected algorithm by harvesting speed signals so
that the substantially absolute grain loss indication is expressed in
terms of weight per unit of surface, said harvesting speed signals being a
function of the ground speed of the machine in combination with the
harvesting width of the machine.
10. The apparatus of claim 8 further comprising convertor means associated
with said grain separation detector means, said further detector means,
and the processor means for coverting the output signals of the detector
means to digital form for application to the processor means.
11. The apparatus of claim 10 wherein the convertor means comprises:
(a) means for converting the grain separation detector output signal and
the further detector output signals into pulsed signal, and
(b) counter means for counting the pulsed signals received from the pulsing
means, multiplier means also being provided for accessing said counter
means in rotation.
12. The apparatus of claim 11 further comprising a buffer means associated
with said counter means into which the counts of the respective counter
means are dumped when the latter is reset.
13. A method of measuring grain loss in a harvesting machine having a
threshing means for receiving crop material containing grain and threshing
grain from said crop material, comprising the steps of:
detecting grain separation at least two spaced apart locations along the
length of the flow path of crop material through a grain handling
mechanism within the harvesting machine, said grain handling mechanism
including a separating means for receiving crop material from said
threshing means and separating grain from waste crop material and a
cleaning means in flow communication with said separating means to receive
grain therefrom and clean residue crop material therefrom to create
cleaned grain;
producing output signals representative of the measurement of grain
separation at each said location;
applying said output signals to a processor means having stored therein a
plurality of algorithms, each said algorithm being expressed as a ratio of
selected said output signals; and
deriving from said processor means through utilization of a selected one of
said algorithms a substantially absolute indication of grain loss from
said grain handling mechanism at a given instant.
14. The method of claim 13 further comprising the steps of:
detecting at least one actual operating condition parameter for said
harvesting machine with at least one operating condition detector along
the flow path of crop material through said harvesting machine;
producing a further output signal representative of each said detected
operating condition parameter;
applying each said further output signal to said processor means with said
output signals; and
comparing said output signals and each said further output signal in a
predetermined manner with predetermined data stored within said processor
means to derive said absolute indication of grain loss.
15. The method of claim 14 wherein said deriving step includes the step of:
selecting one of said algorithms according to the operating condition
parameters determined from said detecting step for utilization in
determining said absolute indication of grain loss from said grain
handling mechanism.
Description
BACKGROUND OF THE INVENTION
This invention relates generally to an apparatus for measuring grain loss
in harvesting machines, and more particularly, to an apparatus that may be
used for measuring grain losses in harvesting machines, lost grain being
that grain which is lost by way of either being entrained in the straw
which is discharged from the combine separating mechanism to the ground or
by way of being discharged together with chaff and other impurities from
the combine cleaning apparatus.
Throughout this specification the reference to "grain"is intended to refer
to that part of the crop which is threshed and separated from the
discardable part of the crop material which is referred to as "straw." In
the following description terms such as "forward", "rearward", "left",
"right" etc. are used which are words of convenience and which are not to
be construed as limiting terms.
Grain loss monitors for harvesting machines are known and these attempt to
monitor the amount of grain which is lost by way of being entrained with
the straw, chaff and other debris and not separated therefrom. To date, no
grain loss monitor has been provided which is able to provide an
indication, in absolute terms, of the magnitude of the actual grain loss
that is occurring during the harvesting operation. Known monitors have
only been able to provide some indication which varies more-or-less
proportionally with the variations in the magnitude of the actual grain
losses without however having been able to establish the correlation
factor between this indication and the actual losses. These known grain
loss monitors rely on impact detectors to "count" a fraction of the grain
which is being discharged with the straw, chaff and other debris at the
back of the machine without knowing however the exact relative proportion
between this fraction and the total actual losses.
A number of problems are encountered over and above the basic problem of
not being able to provide an exact measurement of the amount of grain
being lost. One of the ancillary problems is that known detectors are
unable to distinguish with any assurance between impacts occasioned by
grain and those occasioned by pieces of straw having a nodule at one end
thereof and which can be "seen" by a detector as a grain kernal. This
problem is particularly critical in wet grain conditions.
Another problem with known grain loss monitors is the relatively complex
procedure which has to be adopted to set up the monitor in the first
place. Apart from having to operate a plurality of controls according to
the type of crop and the condition of the crop being harvested (the latter
being likely to change anyway as one proceeds with the harvesting
operation), the operator has to calibrate the monitor to some extent by
way of setting the relevant controls and then physically checking the
straw, chaff and other debris which is being discharged by the machine and
using his practiced eye to decide whether or not the extent of grain loss
is acceptable. If it is not, then the controls are reset and a further
check is made.
When the operator decides that the grain loss is acceptable, he then
attempts to operate the machine so as to keep the grain loss monitor
"reading" at the same value. If the operator does not use his practiced
eye to effect this calibration of a known grain loss monitor, then grain
loss can be relatively high even when the monitor might indicate
otherwise. This is because, if a crop being harvested is of a type or is
in a condition such that it is difficult to separate grain from the straw
in which it is entrained, the detectors will detect very little grain
because, if the latter is not properly separated from the straw, then it
will not impact the detector in the form necessary to be "counted."
Accordingly, in this harvesting situation, the grain loss monitor will
indicate that the grain loss is minimal and probably zero when quite the
reverse situation may pertain. It will also be appreciated that, in a crop
or crop condition which results in an easier separation of grain from the
straw, the grain loss monitor will indicate that there is grain loss
which, while being true, is at a level which is usually significantly less
than for the crop or crop condition having the characteristic of being
difficult to separate the grain from the straw. This thus is the reason
why the practiced eye of the operator is required for calibration
purposes.
It further also will be appreciated that, even with the calibration as
described above, the grain loss monitor still does not provide a "reading"
in absolute figures of the magnitude of the actual losses. Instead, this
monitor "reading"only indicates whether or not the actual losses are at a
generally acceptable level. In addition thereto, variations in the grain
loss monitor "reading" further also may be interpreted to mean that the
actual grain losses vary more-or-less accordingly, i.e. increase or
decrease together with an increased, respectively decreased monitor
"reading" even though there appears not necessarily to exist a linear
correlation therebetween.
Accordingly, it would be desirable to overcome not only this problem of
calibration experienced with known grain loss monitors but, more
importantly, to provide an apparatus which will measure actual loss of
grain.
SUMMARY OF THE INVENTION
According to the present invention an apparatus is provided which includes
detector means associated with the threshing and separating mechanism
and/or the cleaning apparatus of a harvesting machine for measuring grain
loss in said machine, and having at least two detector means associated
with a least either said threshing and separating mechanism or said
cleaning apparatus. The detector means is mounted at spaced apart
locations along the length of the path of the crop material through the
mechanism and/or the apparatus and the detector means is operable to
detect grain separation rates in the mechanism and/or the apparatus at the
locations within the machine and to produce electrical output signals
representative thereof. A processor means to which the output signals are
applied is operable to derive therefrom a substantially absolute
indication of grain loss at a given instant.
Preferably three grain separation detector means are associated with at
least either the threshing and separating mechanism or the cleaning
apparatus. A first detector means is provided either generally at or
adjacent to the receiving end of the separating mechanism or generally at
the midpoint (as seen in fore-and-aft direction) of the cleaning
apparatus. A second detector means is provided generally at or adjacent to
the discharge end of either said separating mechanism or said cleaning
apparatus, while the third detector means is provided generally midway
between said first and second detector means along the length of either
said separating mechanism or said cleaning apparatus. These grain
separation detector means preferably are of the impact type.
The processor means have stored therein predetermined data preferably in
the form of look-up tables, and are operable to compare therewith data
derived from the output signals of the grain separation detector means to
derive therefrom a substantially absolute indication of grain loss.
Furthermore, the processor means may be programmed to accept the manual
input of operating condition parameters and may be operable to compare
these parameters with the predetermined data stored in the processor means
and with data derived from the output signals of the grain separation
detector means to derive therefrom the substantially absolute indication
of grain loss. These operating condition parameters may include both crop
parameters and/or machine parameters, which are representative of at least
one of the following characteristics: type of crop (i.e. wheat, barley,
corn . . . ); condition of crop (ripe, unripe . . . ); crop moisture
content; specific weight of 1000 kernals of grain; amount of material
other than grain (MOG); and ground speed factors (e.g. header width, wheel
diameter).
However, one or more of these operating condition parameters, eventually
together with still other operating condition parameters, alternatively
may be detected by further detector means. These further detector means
could be operable to produce a further signal or signals representative of
the respective operating condition parameters and to apply the signals to
the processor means. These processor means, in this case, would be
programmed to apply the further signals against the predetermined data
stored within the processor means and the data derived from the output
signals of the grain separation detector means to derive therefrom the
substantially absolute indication of grain loss. These further detector
means may sense one or more of the following conditions: crop moisture
content; grain flow; material other than grain (MOG); or ground speed.
In a preferred embodiment, the processor means are programmed with at least
one algorithm against which the data derived from the grain separation
detector means and the operating condition parameter or parameters
inputted by the operator and/or detected with the further detector means,
are applied to derive therefrom said substantially absolute grain loss
indication. In case more than one algorithm is stored, the processor means
is programmed to select the appropriate algorithm for any given
circumstance on the basis of the operating condition parameter or
parameters. The algorithms may be a logistic selection of the ratio or
ratios of pairs of grain separation detector output signals and one or
more operating condition parameters. The processor may calculate grain
loss in terms of weight per unit of time although other approaches, such
as calculations in terms of percentages or weight per unit of surface, are
preferred. This information is indicated on a display unit.
The grain flow and material other than grain (MOG) detectors may be
effected by the flow metering device disclosed in European Patent
Application No. 85.201.187.3. In addition. The grain separation detector
means preferably are of the type such as disclosed in the U.S. Pat.
applications filed concurrently herewith and entitled "Impact Detectors"
and "Grain Loss Monitors for Harvesting Machines." Preferably, this type
of impact detector is employed because of a high saturation point so that
it can be located at a point in the harvesting machine where the incidence
of grain is very much higher than that occurring at the end of the straw
walkers, for example. Thus, such detectors may be located beneath the
threshing and separating mechanism of the harvesting machine so that data
can be derived in respect of grain actually separated from the rest of the
crop material in said mechanism and as is part of the present invention.
Preferably, means are provided for converting the grain separation detector
output signals and the operating condition detector signals into pulsed
signals. Counter means responsive to the convertor means are operable to
count the pulses of the output signals. Multiplexer means are provided to
look at the counts in the counters in rotation, for example every second,
and pass the data obtained therefrom to the processor means so that the
latter can derive an indication of grain loss therefrom. Each counter is
preferably provided with a buffer in order that, when the counter is
reset, the count therein can be dumped in the buffer to allow the counter
to continue counting.
According to a second aspect of the present invention there is provided a
method of measuring grain loss in a harvesting machine which includes the
steps of: detecting grain separation at least two locations within the
machine; producing output signals representative thereof; applying said
output signals to processor means; and deriving therefrom a substantially
absolute indication of grain loss at a given instant.
This method of measuring grain loss may include the following additional
steps: detecting at least one operating condition parameter; producing a
further output signal or signals representative thereof; applying said
further output signal or signals to the processor means; comparing said
output signals and further output signal or signals in the processor
means; and deriving therefrom said substantially absolute indication of
grain loss.
BRIEF DESCRIPTION OF THE DRAWINGS
A method and an apparatus for measuring grain loss in a combine harvester
will now be described in greater detail, by way of example, with reference
to the accompanying drawings wherein:
FIG. 1 is a diagrammatic side view of the combine harvester;
FIG. 2 is an enlarged partial view of FIG. 1 showing the position of grain
detector means;
FIGS. 3 and 4 are views similar to FIG. 2 but illustrating different
threshing and separating means equiped with grain detector means according
to the invention;
FIG. 5 is a graph illustrating the grain separation distribution along the
length of the path of the crop material through the threshing and
separating mechanism on the one hand and the grain loss on the other hand;
FIG. 6 is blocked circuit diagram of the overall apparatus; and
FIGS. 7 and 8 are graphs illustrating the correlation between the grain
loss readings of a known grain loss monitor, respectively the grain loss
monitor according to the present invention and the actual grain losses.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Aspects of the grain loss measuring apparatus according to the present
invention also are disclosed in the copending U.S. patent application No.
335,653 filed concurrently herewith and entitled "Grain Loss Monitors for
Harvesting Machines." The detectors utilized in the present invention
preferably are of the type disclosed in greater program in still another
co-pending U.S. patent application No. 335,620 filed concurrently herewith
and entitled "Impact Detectors" now U.S. Pat. No. 4,953,589. The
descriptive portions of both of these above-identified patent applications
are hereby incorporated herein by reference.
Referring first to FIG. 1, the combine harvester comprises a main frame 1
having a front pair of ground engaging wheels 2 and a pair of smaller
steerable rear wheels 3. The machine is provided with a header 4
comprising a reel 5, a cutterbar 6 and an auger 7 which consolidates cut
crop material centrally of the machine and passes it to a crop elevator 8
which delivers it in a layer to a threshing and separating mechanism
indicated generally at 9 and which may be of the type as disclosed in
greater detail in GB-A-2.063.039, the description of which is included
herein by reference.
This threshing and separating mechanism 9 is shown on a larger scale in
FIG. 2. The rotatable threshing mechanism, which is the forward part
thereof, comprises a rotatable threshing cylinder 18, which is cooperable
with a stationary threshing concave 19 to thresh the crop material and to
separate most of the grain from the rest of the crop material. Rearwardly
of the threshing mechanism 18, 19, a rotatable straw beater 21 and
stationary beater grate 22 are provided which cooperate to transfer the
layer of crop material issuing from the threshing mechanism 18, 19 to the
separating mechanism disposed rearwardly thereof while separating further
grain through the grate 22 from the discardable part of the crop material.
The separating mechanism comprises two transversely disposed rotors 23 and
24 which are cooperable with respective separator concaves 25 and 26. The
forward separator rotor 23 and associated concave 25 have a width which
corresponds to the width of the threshing mechanism 18, 19 and the straw
beater 21 and are disposed to pass the layer of crop material in a
rearward direction across the separator concave 25 while separating
further grain through said concave 25. The rearward separator rotor 24 and
associated concaves 26 have a larger width than the forward separator
rotor 23 and have transversely opposite end portions which extend
transversely beyond the corresponding opposite ends of the forward rotor
23. The rearward rotor 24 and associated concaves 26 are disposed to
divide the layer received from the forward rotor 23 in two halves and to
convey these halves spirally around the rearward rotor 24 in transversely
opposite paths towards the discharge outlets at the respective opposite
ends of the housing comprising the rotor 24 for discharge therethrough to
the ground. During this spiral movement, the crop material again is
subjected to a grain separating action resulting in still further grain
being separated through he concaves 26.
Grain separated through the threshing concave 19, the beater grate 22, the
separator concave 25 and the central sections of the separator concaves 26
is received directly onto the cleaning apparatus 12. Grain separated
through the transversely opposite end portions of the separator concaves
26 falls to auger troughs 11 comprising transverse augers 10 for conveying
this grain to the cleaning apparatus 12. Threshed and separated grain is
cleaned in a conventional manner in the cleaning apparatus 12 which
comprises upper and lower sieves 61, 62 and a cleaning fan 63. Cleaned
grain is received in a grain auger 13 and transferred therefrom to a grain
tank 14. Tailings are received in a tailings auger 15 and taken therefrom
for reprocessing first by a tailings rethresher means and next by the
cleaning apparatus 12. Straw issuing from the threshing and separating
mechanism 9 and chaff and other debris issuing from the cleaning apparatus
12 are discharged to the ground through a straw hood 16. Grain that is
discharged together with this straw, chaff and other debris forms the
grain loss. The apparatus according to the present invention aims at
providing an indication, in absolute figures, of the magnitude of this
grain loss.
The rotary threshing and separating mechanism 9 briefly described hereabove
is one of various types of threshing and separating mechanisms known in
the art. The more conventional threshing and separating mechanism includes
straw walker type separator means which may be substituted for the
separator rotor 24 and associated separator concaves 26 according to FIGS.
1 and 2. This so-called conventional threshing and separating mechanism is
illustrated in FIG. 3. 1n still another arrangement shown in FIG. 4, the
entire threshing and separating mechanism is of a different type and
comprises one or two axial flow threshing and separating rotors 57
cooperable with associated threshing and separating concaves 58. A twin
rotor axial flow combine of this type is disclosed in greater detail in
GB-A-1.399.601, which is also incorporated herein by reference.
The present invention is applicable on anyone of these combine harvesters
and may be used for monitoring the grain losses occurring at the discharge
end of either the separating mechanism, or the cleaning apparatus or of
both said separating mechanism and said cleaning apparatus.
Grain loss sensors conventionally have been provided rearwardly of the
discharge end of the separating mechanism and/or the upper cleaning sieve
for a fraction of the lost grain kernals to impact thereon as they are
discharged to the ground and so as to thereby provide an indication of the
magnitude of the actual grain loss that is occurring. Occasionally such
grain loss sensors also have been installed, as has been shown in
EP-0117.587, forwardly of and adjacent to the discharge end of the
separator mechanism. Practice has shown, as has been explained in the
introduction of this description, that these prior art arrangements give
only a very inaccurate indication of the magnitude of the actual grain
losses and that, by no means, this indication can be used to generate an
indication of the grain losses in absolute figures.
It has been found, in connection with the present invention, that a better
indication of the actual grain losses can be derived from a plurality of
measurements of the grain separation at different locations along the
length of the threshing and separating mechanism, and/or the cleaning
apparatus, in as much as these measurements of grain separation permit a
"prediction" of the actual losses that occur rearwardly of the discharge
end thereof. It thus should be remarked that the arrangement according to
the present invention basically measures grain separated in the separating
mechanism and/or the cleaning apparatus and derives an indication for the
actual grain losses therefrom, while that prior art arrangements always
have attempted to directly measure a fraction of the actual grain losses.
While in the following description, reference will be made mainly only to
the threshing and separating mechanism and to the losses occurring at the
discharge end thereof, it should be understood that the same also applies
to the cleaning apparatus.
Considering the grain separation rate along the length of the path of the
crop material through the threshing and separating mechanism, it has been
noticed that this separation rate decreases from front to rear. It further
also has been noticed that, when the separation rate proximate to the
discharge end is higher, the total actual losses rearwardly of this
discharge end also are higher. FIG. 5 schematically illustrates these
findings in a graph wherein the length of the crop path through the
threshing and separating mechanism is indicated on the x-axis and the
separation rate is indicated on the y-axis. The discharge end of the
threshing and separating mechanism is indicated on the x-axis at A and the
surface X beneath the extrapolation of the separation rate curve C beyond
the discharge end A is indicative of the actual grain loss occurring in a
particular situation.
As indicated in this FIG. 5 the separation rate curve C may vary dependent
on various conditions. Many influences define the precise location and
shape of this curve C. However, when in any particular case, a given
number of points along the length of the curve C, say e.g. three points,
are determined (by measurement of the grain separation) then the shape and
position of this curve C is pretty well defined and, as a consequence, the
actual losses that occur at the discharge end of the threshing and
separating mechanism, in principle, also can be derived rather accurately
therefrom.
In accordance with the present invention, a plurality of grain detector
means in the form of impact detectors are provided along the length of the
path of the crop material through the threshing and separating mechanism.
In a preferred embodiment sensors are provided only at three locations.
However, it also should be appreciated that more sensors may be provided
to further improve the accuracy of the indication. 0n the other hand, in
certain circumstances, the skilled in the art, will find that only two
sensors equally will provide satisfactory results.
The sensors preferably are provided only along the length of the separating
portion of the threshing and separating mechanism (or, respectively along
the length of the rear half of the cleaning sieves). One of said sensors
further also preferably is provided at the same location as where the
prior art grain loss sensor members were provided, i.e. either immediately
behind or immediately in front of the discharge end of the separating
mechanism, respectively the cleaning apparatus.
With reference to FIGS. 1 to 4 the sensors associated with the threshing
and separating mechanism are indicated at S1, S2 and S3. With reference to
FIG. 1, the sensor associated with the cleaning apparatus are indicated at
Sl', S2'and S3'. As already indicated and as the characteristics of the
apparatus according to the invention are substantially the same
irrespective of whether this apparatus is provided to monitor either the
separator grain losses or the cleaning grain losses, only the operation
thereof in combination with the threshing and separating mechanism will be
described hereafter.
With particular reference now to FIG. 2, the detector S1 is located
underneath and generally at the mid-point of the separator concave 25 (or
seen in the direction of flow of crop material across the concave). The
detector S2 is provided adjacent to one of the separator concaves 26 at a
point generally midway (again as seen in the direction of flow of the crop
material) between the inlet and the outlets of the rotor housing
comprising said concaves 26 and the sensor S3 is provided adjacent to one
of the offset concaves 26 and proximate to one of the discharge outlets of
the rotor housing comprising said concaves 26. The sensor S3 thus is
provided generally at the same location as where the prior art grain loss
sensor according EP-A-0.117.587 has been provided.
In FIG. 2, additional optional sensors S4 and S5 also have been shown;
sensor S4 being located generally adjacent the receiving edge of the
separator concave 25 and the sensor S5 being provided generally at the
transition between the concaves 25 and 26. As seen in the direction of
flow of the crop material through the separating mechanism, the sensors
are provided in the following sequence : S4, S1, S5, S2 and S3. Whenever
possible, the sensors S1-S5 preferably are mounted at a specific angle to
the tangent to the rotors 23 and 24 with which they are associated; this
angle being in the range of 30.degree. to 35.degree. in order to avoid
impacts upon the sensor surfaces at right angles by grain and straw which
issues straight radially out of the concaves. Apart from this orientation
of the sensor surfaces relative to the tangent as described, it is also
necessary to position the sensors at an angle of at least 35.degree.
relative to the horizontal so as to avoid accumulation of material on top
of the impact surfaces thereof.
Referring now to FIG. 3, it will be seen that the sensors S1, S2 and S3 are
provided respectively underneath the separator concave 25 generally at a
mid-point thereof; within a straw walker 55 again generally at a mid-point
thereof and finally generally at the rearward discharge end of said straw
walker 55. With reference to FIG. 4 illustrating the axial flow type
threshing and separating mechanism, the sensors S1, S2 and S3 are provided
respectively underneath the middle section of the threshing and separating
concave 58 and the forward and rearward edges of the concave 59 associated
with the discharge beater 60.
Referring now to FIG. 6 of the drawings, the apparatus for measuring grain
loss in accordance with the present invention will now be described. The
sensor or detectors S1, S2 and S3 are, as already mentioned, of the impact
type and produce an analogue signal representative of each impact
detected. The sensors S1, S2 and S3 are illustrated in FIG. 6, together
with the further sensors S4 and S5 and associated circuitry, which are
representative of any additional sensors which may be employed at any
desired location in the combine harvester and which equally are of the
impact type.
Each sensor S1-S5 has associated with it a pulse former 32 which converts
the analogue signals into calibrated pulsed signals; these pulsed signals
being applied to counters 33 which have associated therewith buffers 34
into which the counts from the counters are dumped when the latter are
reset, thus allowing the counters to continue counting. The output of each
buffer 34 is applied to a multiplexer 35 which has a two-way connection
with a microprocessor 37 to which also are connected a memory 36, a
display unit 38 and a key pad 50. The memory 36 may be programmed with
desired look-up tables and algorithms for calculating grain loss from the
input data. The memory 36 also accepts input from the key pad 50 which is
controlled by the machine operator to input selected factors, such as type
and condition of the crop material, different ground speed factors,
cutterbar width and wheel diameter.
The memory 36 further also accepts the counts from the counters 33 for
storage in rotating registers in a manner to enable the microprocessor 37
to take into account the fact that it takes some time for crop material to
be processed in the separating mechanism and to sequentially move past the
locations of the various sensors S1-S5 from the inlet to the outlet of the
separating mechanism. In other words, the microprocessor 37 does not
compare the signals generated by all sensors S1-S5 at any given moment in
time but instead compares related signals generated by the sensors S1-S5
at staggered time intervals. The system thus comprises time delays which
are operable to synchronise the outputs of the sensors S1-S5 positioned at
different locations in the process. The system further also includes
filter means for cancelling out or greatly reducing the influences of any
short time, abrupt fluctuations in the magnitude of the signals.
In addition to the sensors S1-S5 for detecting separated grain, the grain
loss measurement apparatus also comprises a plurality of further sensors
S11-S14, which are so disposed as to produce signals respresentative of,
respectively, the moisture content of the crop being harvested; the grain
flow in the combine harvester (i.e. the flow rate of the total amount of
grain being harvested); the flow rate of all material other than grain
(i.e. mainly straw) in the combine harvester and the ground speed. The
moisture content sensor S11 may be in the form of a suitable humidity
sensor that may be mounted within the straw elevator housing 8. The
sensing of the grain flow may be effected by way of the flow metering
device disclosed in European Patent Application No. 0.208.025 and which
may be associated with the clean grain elevator 27. A similar flow
metering device may be provided within the straw hood 16 for sensing the
MOG flow. Alternatively an indication of the MOG flow may be obtained by
means of a torque sensor that may be provided within the drive line to the
header auger 7. The ground speed sensor S14 may be associated with one of
the steerable rear wheels 3 and may be in the form of an rpm counter.
The output of each additional sensor S11-S14 is applied to an associated
pulse former 43, a corresponding counter 44 and a corresponding buffer 45
before being applied to the multiplexer 35 in the same way as is done with
the output signals from the sensors S1-S5.
In the graph of FIG. 7 the relationship between actual losses (y-axis) and
the indication of these losses obtained with a conventional grain loss
monitor (x-axis) is illustrated. The various curves are indicative for
different crops and crop conditions. It thus will be noticed therefrom
that the relationship between the monitor reading and the actual grain
losses appears to be far from linear. Moreover, it also will be noticed
that this relationship varies widely dependent on a.o. the type of crop
and the crop condition. As a consequence it is impossible for a combine
operator to derive from a given grain loss reading the actual grain loss
level because, amongst other things, he does not know which one of the
many curves is applicable in the condition he is operating under.
Furthermore, any given variation in the grain loss reading corresponds to
a larger or smaller variation in the actual losses dependent on the
location along any given curve. This even further complicates intelligent
utilization of known grain loss monitors.
Consequently, it is highly desirable to obtain a grain loss reading of some
type which has a linear relation with the actual grain loss on the one
hand and of which the spreading of the linear relation, dependent on the
crop and crop condition, is kept to a minimum on the other hand. Although,
it would be ideal if this spreading could be eliminated altogether. These
requirments are illustrated in FIG. 8 and may be obtained by the present
invention as will be described hereafter in greater detail.
It has been found that, when using a particular algorithm of the readings
obtained from the sensors S1 S2 and S3, a linear relation indeed exists
between this algorithm and the actual grain losses in weight per unit of
time (e.g. gram/second). One such algorithm is:
##EQU1##
However, other algorithms also may be used in other circumstances, such
as:
##EQU2##
These algorithms of the grain sensor readings are characteristic values
calculated from readings which are indicative of the grain separation in
the separation process. These algorithms, which are in the form of ratios
of impact detector signals, neutralize certain factors, such as the
specific weight of the grain, that may have an influence on the sensor
output signals.
However, an indication of the grain losses in weight per unit of time still
is not very useful either. The more useful and meaningful indications of
the actual grain losses should be expressed in terms of either a
percentage (i.e. of the total amount of grain harvested) or weight per
unit of surface (e.g. kg/ha). Starting from the indication in weight per
unit of time, an indication of the actual grain loss in terms of
percentage is obtained by dividing the aforementioned algorithm of the
grain separation sensor readings by the grain flow readings obtained from
the grain flow sensor S12. If the results of the algorithm of the grain
separation sensor readings is indicated by A, then the new algorithm
giving a percentage indication is expressed by :
##EQU3##
The indication of the actual grain losses in terms of weight per unit of
surface is obtained by dividing the algorithm of the grain separation
sensor reading by speed readings, which may be derived from the rpm
readings from sensor S14 in combination with the header width and the
wheel diameter. The latter two values normally need to be fed into the
microprocessor by the combine operator. In simplified form, the new
algorithm giving the indication of the actual losses in weight per unit of
surface is expressed by :
##EQU4##
In an attempt to reduce (or indeed ideally eliminate) the spreading of the
relation between the actual grain losses and the algorithms B and C
resulting from variations in the crops and crop conditions, correction
factors are applied against said algorithms B and C. A first correction
factor F1 takes into account crop parameters such as the type of crop
(e.g. wheat, corn, barley, etc.) and specific weight of the crop. This
first correction factor F1 may be derived from the look-up tables in the
memory 36 in response to the input provided by the operator. The
variations in crop parameters also may dictate a different algorithm A
against which the grain sensor readings S1-S5 should be applied. This
again is derived from look-up tables in the memory 36.
A second correction factor F2 takes into account crop condition parameters
such as moisture content and MOG (material other than grain). These crop
condition parameters are sensed with the sensors S11 and S13, the readings
of which are applied against look-up tables in the memory 36 for
determining the appropriate correction factor F2. This second correction
factor F2 eventually also may take into account the degree of ripeness of
the crop, this parameter normally being inputted to the processor means 37
by the operator. Again the variations in crop condition parameters also
may dictate a different algorithm A against which the grain sensor
readings S1-S5 should be applied. Similarly as indicated before, this may
be derived from look-up tables in the memory 36 against which the readings
of the sensors S11 and S13 are applied.
In summary, the corrected algorithms B' and C' thus can be expressed by:
.eta.
B'=F1 .times.F2 .times.B
C'=Fl .times.F2 .times.C
In applying the foregoing principles in practice with the apparatus and the
arrangement according to the present invention, the operator first has to
input factors such as the wheel diameter (provided this has not yet been
done by the manufacturer or the dealer), the header width and the type of
crop to be harvested. During the subsequent operation of the grain loss
measuring apparatus, the multiplexer 35 looks at the counts of the
counters 34 and 45 in rotation. Each counter is accessed periodically and
the data obtained is passed to the microprocessor 37. Based on such
factors as the type of crop material being harvested, the moisture content
and the amount of MOG measured by the sensors Sll and S13, the
microprocessor 37 determines practically continuously, through access to
the look-up tables of the memory 36, which algorithm A ought to be used
for processing the grain sensor readings S1-S5. The microprocessor 37
further also continuously calculates the algorithm A using therefore the
sensor readings S1-S5.
These calculated characteristic values of grain separation in the combine
harvester process are corrected with the correction factors F1 and F2
which again may be derived from look-up tables in the memory 36 as already
explained and against which crop parameters and crop condition parameters
sensed by the sensors S11 and S13 may be applied.
To arrive at the indication of the actual grain losses in terms of either
percentages of the total yield or weight per unit of surface, the
corrected algorithms, as obtained in the way as indicated above, are
divided in the microprocessor 37 either by the grain flow readings
obtained from the sensor S12 or by measures representative of the
harvesting speed or capacity in, for example, hectares per hour and which
themselves are derived from the rpm readings from the rpm sensor S14 in
combination with the header width and wheel diameter values previously
stored in the memory 36 by the operator.
The foregoing process thus provides on-the-go indications, in absolute
figures, of the grain loss rates of the threshing and separating process
(and/or of the cleaning process) in a combine harvester in terms of
percentages of total yield and/or weight per unit of surface; these
indications being displayed on the display unit 38.
The present invention represents an extremely significant advance in the
art of crop harvesting from the standpoint of being able to measure in
substantially absolute terms the amount of crop (grain) being lost and
thus being able to alter the operating conditions of the machine to
maintain that loss at an acceptable level while optimizing the harvesting
speed. To date, no apparatus for providing such a measurement of grain
loss has been produced.
While the preferred structure, in which the principles of the present
invention have been incorporated, is described above and is shown in the
accompanying drawings, it is to be understood that the invention is not to
be limited to the particular details as described above and shown in said
drawings, but that, in fact, widely different means may be employed in the
practice of the broader aspects of the invention.
As an example, it is conceivable that acceptable results already can be
obtained with an apparatus generally as described above but wherein the
moisture content sensor S11 and the MOG sensor S13 are left out. In this
case, the operator eventually may have to key in some more parameters
prior to starting operation. The microprocessor thus may be programmed to
enable the input of specific average moisture content values on the one
hand and average MOG values on the other hand.
In case in addition to the foregoing also the grain flow sensor S12 and the
speed sensor S14 would be left out, then the apparatus still could measure
the absolute grain losses in terms of weight per unit of time (e.g.
gram/sec). As already indicated, such an indication is less meaningful
than the indications obtained with the preferred embodiment of the present
invention. Nevertheless, the foregoing already forms a remarkable advance
with respect to the state of the art.
It thus is conceivable that in its simplest form, the grain loss monitor
according to the invention comprises a microprocessor to which at least a
pair of grain impact sensors are coupled which are operatively associated
with the threshing and separating mechanism and/or the cleaning apparatus
at different locations along the path of the crop material through the
machine and which are operable to produce signals representative of the
grain separation rates in said mechanism; said microprocessor having
stored therein predetermined data and being programmed to enable the input
of certain operating condition parameters and to compare with said
predetermined data and said operating condition parameters the signals
received from the grain impact sensors to derive therefrom a grain loss
indication in substantially absolute figures. The type and condition of
the crop material eventually together with other aspects may determine
said operating condition parameters. If the foregoing apparatus further
also comprises a speed sensor S14 and/or a grain flow sensor S12 then the
grain loss indications can be expressed in terms of weight per unit of
surface or percentage of total yield respectively.
It further also will be appreciated that the display means 38 may appear in
different forms such as e.g. a needle which is movable relative to a scale
or an LCD.
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